Antiretroviral Therapy (ART)
This therapy includes medications which interfere with the growth of virus causing HIV. These drugs are classified according to the phases of HIV in which they prevent the virus growth.
The different phases of HIV are described below to classify the ART drugs.
1. The virus is introduced in the blood stream and transports freely.
2. The virus gets attached to the cell.
3. All the matter of the virus is transferred to the cell.
4. The reverse transcriptase enzyme uses this material of the virus to produce HIV DNA.
5. The HIV integrase enzyme introduces this HIV DNA into the chromosome of the cell. This gives rise to the HIV infection.
6. As the infected cell is reproduced, the HIV DNA is multiplied. This acts as the content for the HIV virus.
7. Multiple contents combine together to form a new virus.
8. Budding is defined as the process where the newly produced virus leaves the infected cell.
9. This virus then dissociates from the infected cell.
10. The protease enzyme extracts the raw material which combines to form a new virus.
ART drugs are categorized into five groups as below.
• nucleoside reverse transcriptase inhibitors (NRTIs or nukes) – These drugs interfere with the step 4 described above. The production of DNA of HIV is prevented.
• Non-nucleoside reverse transcriptase inhibitors, (non-nukes or NNRTIs) - These drugs interfere with the step 4 described above. The mechanism is different from that of the nukes.
• Protease inhibitors or PIs – As per the name, these drugs interrupt step 10.
• Entry inhibitors – These drugs prevent the virus from entering the cell as described in step 2.
• HIV integrase inhibitors – These drugs act by interrupting the step 5. The genetic material of the virus is prevented from entering the chromosome of the cell of human body.